Hunt for the Giant Leech

"What creatures?"Well, you could step on an electric
fish and get a nasty shock, or step in a pool of piranha and get a nasty
de-fleshing. (Check out that piranha's dentition, will you?) "As
long as it's the rainy season and they have enough to eat, you're
okay," Mark yells over. You might surprise a capybara, the world's
largest rodent—this one probably weighs as much as a German shepherd. If
you come across a caiman, pray it's the spectacled (lower right in image) and not
the black, which can reach over 20 feet in length. So, for that matter, can the
anaconda, which loves to wrap its thigh-thick self around submerged plants in
this swamp. And then, of course, there's the giant Amazonian leech, of
which a French scientist wrote in 1899, "a few of these enormous leeches
are sufficient to kill a cow or a horse."